Single-phase gas or vapor electric device.



P. H. THOMAS. SINGLE PHASE GAS 0R VAPOR ELECTRIC DEVICE. APPLICATION EILED JAN. 29. I910.

l 1 88.5 75. Pate-Med June 27, 1916.

mag/var tain' current through the negative electrode has once been broken down,

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PERCY H. THOMAS, 0F MONTCLAIR, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO COOPER HEWITT ELECTRIC COMPANY, OF HOBOKEN, NEW JERSEY, A

CORPORATION OF NEW JERSEY.

SINGLE-PHASE GAS OR VAPOR ELECTRIC DEVICE.

Specification of Letters Patent.

Patented June 2'7, 1916.

Original application filed June 13, 1903, Serial No. 161,282. Patent No. 1,110,582, dated September 15, 1914. Divided and this application filed January 29, 1910. Serial No. 540,738.

Vapor Electric Devices, of which the following is a specification.

In an apparatus of the character shown in certain patents to Peter Cooper Hewitt, for example elusive, dated September 17th, 1901, which is operated on direct current circuits, it has been customary in starting to apply to the terminals of the apparatus a momentary current of higher potential than that upon which the apparatus is designed to be operated. In employing alternating currents, it is possible to apply 'to the starting band a higher potential derived from the supply circuit.

When the described reluctance to starting current may continue to flow through the apparatus provided the applied electro-motive-force is sufficiently high and also provided that the direction of flow be maintained uniformly. When, however, currents of varying value or of alternate direction are applied to the apparatus, the electrode reluctance is liable to be re-formed should the drop below a certain minimum, and is certain to be re-formed when thefdirection of flow is reversed. Thus in operating apparatus of this class by means of alternating currents or currents which vary considerably in value, provision has to be made for reenforcing the lower value. when the current is of uniform direction and for repeatedly starting the apparatus whenever the direction of the current changes.

- It hasbeen proposed to provide means for the purpose in icated by placing a choke coil in series with the apparatus which will store energy while the current is increasing and discharge the stored energy or a portion of it in the original direction of flow when the current falls. With a choke coil of suflicient capacity, the rising current will be suflicient to mainifntilthe supply circuit shall again tend to increase; the curre t flow in the proper di- Patents 682,690 to 682,699 in current value the energy stored on rection. In connection withthis general arrangement of circuits and apparatus, various organizations have been proposed for preventing the negative alternations from undoing the work of the positives. For example, the amount of energy required from the choke coil is considerably lessened if a path be provided for the negative alterna-v tions through the apparatus by means of a second positive electrode. With such an organization, both the positive and negative alternations tend to pass through the apparatus in the same direction. Meanwhile, the function of the choke coil in delivering energy enough to supply current for the short period between alternations is constantly called into play.

It might be supposed that in operating the vapor apparatus upon a single phase alternating current, the capacity of the choke coil might have to be considerable, but I have found that in order to maintain the operation of the apparatus after it has once been started, the choke coil need not be of excessive size. It is desirable, however, that an extra potential should be applied to enable the choke coil in the first alternation after starting to absorb a sufficient amount of energy so that it may discharge the energy necessary to maintain the apparatus over the first zero point, without falling below the minimum current.

It is the object of the present invention to provide means for supplying this extra initial potential, as will presently appear, it being understood that the additional volt age thus withdrawn from the source will generally be removed after the starting of the apparatus. This makes it possible to obtain economical conditions during operation, and provides that the extra potential called into use at the starting of the apparatus shall constitute only a temporary demand upon the system.

I have illustrated my invention in the accompanying drawing which shows a diagrammatic illustration of my invention as applied to .a gas or vapor electric apparatus.

1 is the container-of. a mercury vapor device of the character described above, for example a rectifier, the same containing, in this instance, a negative electrode, 5, of

which may be of iron. I show as well a supplemental positive electrode, 4, which may also be of iron.

The device is provided with a starting band, 6, located in proximity to the negative electrode 5 and connected to a suitable source of supply to be described.

The supply circuit for the device 1s illustrated by the conductors, 13, 13, between which is arranged the primary, 37, of a transformer whose secondary is shown at 38. One terminal of the secondary is connected to the starting band 6 and the other is connected to one main 13.

The conductors 13 are joined to the windings, 21, of an auto-transformer. The winding 21 is connected at its opposite terminals by means of wires, 9 and 10, to the positive electrodes 2 and 3, while the secondary winding 32 of a transformer 30, whose primary winding is 31, is joined by a wire, 22, to the supplemental electrode 4:. The secondary winding 32 is also joined to one of the mains 13.

At the neutral point between the terminals of the winding 21, the wire 8 is joined to the said winding, and is also joined through the inductance coil, 7, to the negative electrode.

The conductors, 13, 13 are assumed to be connected with a source of single-phase alternating current, and when the circuit of the said source is closed, throwing potential on the primary winding, 37, the secondary winding, 38, receives a high voltage, which is impressed upon the electrode 5 and the starting band 6 in such a way as to produce a critical strain at the surface of the negative electrode, breaking down its resistance and allowing the positive potential on one of the electrodes 2, 3 or 4 to start the lamp into operation, The operation of the rectifier is then as follows: Assuming, for example, that the electrode 2 (neglecting the electrode 4 for the moment) has a positive potential with regard to the negative electrode .at the time of the application of the critical strain, current flows from 2 to 5, reaching finally the proper value for the electro-motiveeforce supplied and at the same time storing energy in the choke coil 7. During the latter part of the first alternation, as the voltage upon the positive electrode 2 falls to zero, the energy previously stored in the choke coil 7 continues the flow of current in the original direction through the coil until the potential upon the electrode 3 becomes positive in its turn, whereupon the electrode 3 will itself support the current through the rectifier and, as its value rises in the second alternation, will increase the current through the choke coil 7 to the maximum at the time at which it is returning toward zero. As before when the voltage of the electrode 3 becomes too small after starting from to support the current through the choke coil 7, this coil supplies energy keeping the current flowing, though at a decreasing intensity, until the electrode 2 after having had a negative value during the second alternation again becomes positive in the third alternation, when it is utilized to again support the current through the rectifier and the choke coil, 7, and so on, as long as the rectifier operates.

The function of the secondary winding 32 and the supplementary positive electrode 4 is to supply an additional electro-motiveforce during the alternation within which the critical or starting strain is applied. It is evident that during this first alternation, the current must reach its maximum value zero, whereas, when once the rectifier is operating normally, this maximum current must be reached in one alternation, starting, not from zero, but from the minimum valuereached during the operation which must at "least be the minimum operating current of the rectifier. Once the lamp has reached a normal running condition, the supplementary voltage supplied by the winding 32 through the supplementary positive is no longer required and in fact will cause a waste of energy and disturbance of the operation of the rectifier and should be removed from further operation.

I may use for the supplementary transformer a transformer 30, having considerable magnetic leakage between the primary and secondary windings 31 and 32. As soon as the rectifier is started in the manner already described, the magnetic leakage in the transformer 30 will come into play to check the flow of current through the conductor 22, thus practically controlling that part of the circuit as may be desired.

I also show means for creating a phase difi'erence between the voltage applied to the starting band 6 and that applied to the supplementary electrode 4. In practice, I find it advantageous to give to the current applied to the starting band a lead or lag, depending upon the circuit conditions. This can be accomplished by the means illustrated, where, as already described, the primary, 37, of a transformer, 36, is connected between the supply wires 13, 13 while the secondary, 38, is connected between one of the conductors 13 and the starting band 6. In shunt to the primary I may arrange a resistance, 39, and in series therewith an inductance device, 40, the same being so proportioned as to give the necessary lag to the secondary current. This lag in the current exciting the transformer, 36, results as follows: The inductance device, 40, impresses a lagging phase upon the current traversing its circuit with respect to the voltage of the mains, 13, 13, that is, con- I 2. In a system of electrical sidering the sum of the two currents traversing the divided circuit containing the branches constituted by resistance 39 and the primary 37 this current, as a whole, will lag behind the potential of the mains 13 since this total current is the current traversing the inductance device 40. But the portion of the total current traversing the branch containing the primary winding, 37, must lag behind the current in the branch containing the resistance, 39, since the magnetizing current of the transformer primary such as the windingy37, is known to be a lagging current, though lagging less than 90 degrees with the ordinary type of transformer. Therefore the winding in the pri mary, 37, will lag behind the mains, 13, somewhat more than the current in the inductance device, 40, lags behind the mains, 13.

This application is a division of my application Serial Number 161,282, filed June 13th, 1908. I

I claim as my invention:

1. In a system of electrical distribution,

the combination w1th an alternating supply and a mercury vapor rectifier comprising a' highly exhausted container and a plurality of anodes and a vaporizable cathode'therei n, of a supply winding for one of said anodes, a cooperating energizing winding, and means for providing magnetic leakage-between said windings.

distribution,

the combination with an alternating supply and a mercury vapor rectifier comprising a highly exhausted. container, anodes and a common cathode therein of primary and secondary windings supplying one of said anodes'and means for causing currents to said anode to produce magnetic leakage between said windings independent of current to other anodes.

3'. In a system of electrical distribution, the combination with an alternating supply and a mercury vapor rectifier comprising a highly exhausted container, anodes and a common cathode therein of primary and secondary windings, and cooperating means for supplying current to an anode and for controlling said current by magnetic leak- 4. The combination with an alternating current supply circuit, a vapor rectifier comprising a liquid cathode and suitable anodes, means for passing energy from said supply circuit to said rectifier, said means including a transformer between said supply and at least one of said anodes, and means for introducing magnetic leakage into said transformer.

Signed at New York, in the county of New York and State of New York, this 28th day of January, A. D. 1910.

PERCY H. THOMAS.

Witnesses:

WM. H. CAPEL, THos. BROWN. 

